Patent GB-584692-A (GB)
Title: New monoazo dyestuffs
IPC: C09B29/06
Filed: 1944-08-28
Abstract: Monazo dyestuffs are manufactured by coupling a diazotized p-nitraniline, which may carry substituents other than sulphonic acid, carboxylic acid or cyano groups, with the sulphuric ester of an N-hydroxyalkyl-N-phenyl- or naphthyl-alkylaniline (the last-mentioned alkyl residue containing 2, 3 or 4 carbon atoms), which may carry further substituents other than sulphonic acid or carboxyl substituents subject to its being capable of coupling in the para-position to the nitrogen atom, or with a salt thereof. Alternatively, the free N-hydroxyalkyl compound is used as coupling component and the dyestuff is converted into its sulphuric ester by treatment with sulphuric acid or other known reagent for this purpose.  The products, in the form of their alkali metal or ammonium salts, dye cellulose acetate artificial silk in dischargeable violet, brown, orange, crimson and red shades from a neutral, slightly acid or slightly alkaline bath, e.g. from a neutral bath containing Glauber's salt or sodium chloride, and are suitable for application from dilute or "long" liquors such as are employed with the winch machine.  They may also be used for printing cellulose acetate artificial silk and for dyeing wool, natural silk, tin-weighted silk, leather and linear superpolyamide fibres such as nylon.  Examples describe the production of the following dyestuffs: p-nitraniline --> the sodium salt of the sulphuric ester of N-b -hydroxyethyl-N-a 1- or b 1-phenylethylaniline, N-b -hydroxyethyl-N-g -1 phenylpropylaniline, N-b -hydroxyethyl-N-b 1-phenylethyl-m-aminotoluene, m-chloraniline or m-aminoanisole, N - b  - hydroxyethyl - N - b 1-(p-tolyl- or 1 - naphthyl) - ethylaniline, or N - b  - or g -hydroxy-n-propyl-N-b 1-phenylethylaniline; o-chloro-p-nitraniline --> the sodium salt of the sulphuric ester of N-b -hydroxyethyl-N-a 1-or b 1-phenylethylaniline or N-b -hydroxyethyl-N-g 1-phenylpropylaniline; 2 : 6 - dichloro - 4 - nitraniline --> the sodium salt of the sulphuric ester of N-b -hydroxyethyl-N-a 1- or b 1-phenylethylaniline or N - b  - hydroxyethyl - N - b 1-p-tolylethylaniline; 2 : 4-dinitroaniline --> the sodium salt of the sulphuric ester of N-b N-hydroxyethyl-N-a 1- or b 1-phenylethylaniline; 6-chloro-2 : 4-dinitroaniline --> the sodium salt of the sulphuric ester of N-b -hydroxyethyl-N - b 1 - phenylethyl - m - aminotoluene; 2 : 6-di-bromo-4-nitroaniline --> N-b -hydroxyethyl-N - b 1-phenyl- or p-tolyl-ethylaniline sulphuric ester; 2-bromo-4-nitraniline-->N-b -hydroxyethyl-N-b 1 -phenylethylaniline sulphuric ester; 6-bromo-2 : 4-dinitroaniline-->N-b -hydroxyethyl - N - b 1-phenylethyl-2-methoxy-5-methylaniline sulphuric ester.  In a further example, p-nitraniline is diazotized and coupled with N - b - hydroxyethyl - N - b 1 - phenylethylaniline, and the product is treated with 75-95 per cent sulphuric acid.  Other components specified are: diazo components: 2 : 5 - dichloro - 4 - nitraniline, 2 - bromo - 6 - chloro - 4 - nitraniline, 5 - nitro - 2 - aminoanisole and 5 - nitro - 2 - aminotoluene; coupling components: N-b -hydroxyethyl - N - b 1-phenylethyl-m-acetylaminoaniline, N - b - phenylethyl - N - e 1 - hydroxy - n - amyl - aniline and N - b  - hydroxyethyl - N - b 1 - (2 - naphthyl)-ethylaniline. Specifications 181,750 and 237,739, [both in Class 2 (iii)], are referred to. Samples have been furnished under Sect. 2 (5) of the dyestuffs p-nitraniline or o-chloro-p-nitraniline --> the sodium salt of the sulphuric ester of N-d -phenylbutyl-N-b 1-hydroxyethylaniline.  N - b - Hydroxyethyl- and g  - hydroxypropyl - N - phenyl- or naphthyl-alkylanilines are obtainable by reacting the b -hydroxyethyl- or g -hydroxypropyl-aniline with the appropriate aralkyl bromide (e.g. N-b -hydroxyethyl-m-toluidine, m-chloraniline or m-aminoanisole with b -phenylethyl bromide, or N-b -hydroxyethylaniline with d -phenylbutyl bromide) in boiling aqueous medium in the presence of chalk, or, in some cases, by similarly reacting the N-aralkylaniline with the appropriate chlorhydrin (e.g. N-b -phenylethylaniline or N-g -phenylpropylaniline with ethylene chlorhydrin).  N - b  - Hydroxypropyl - N - phenyl- or naphthyl - naphthyl-alkylanilines are obtainable by reacting the appropriate N-aralkylaniline with propylene oxide at about 160 DEG  C.  N-e -Hydroxyamyl - N - phenyl- or naphthyl - alkylanilines are obtainable by reacting the primary arylamine with e -chloroamyl acetate in the presence of an acid-binding agent, reacting the product with the appropriate aralkyl bromide, and hydrolysing the acetoxy group. Sulphuric esters are obtainable by treating the foregoing hydroxyalkyl compounds with chlorosulphonic acid in ethylene dichloride or tetrachlorethane.  N - b  - Phenylethylaniline and N-g -phenylpropylaniline are obtainable by heating aniline with b -phenylethyl bromide and g -phenyl-n-propyl bromide respectively.